Attenuator control circuit having a plurality of branches

Abstract

A split power control circuit includes a solid state switch and a circuit or circuit element, such as a relatively large resistance or reactance connected between an RF signal line and ground. In order to provide relatively more precise control and thus relatively finer adjustment of the RF signal line, the RF signal line is split into a plurality of branches, with the switched control circuit or element connected to one or more of the branches. In another embodiment of the present invention, a solid state switch and serially connected circuit or circuit element, such as a resistance or reactance, are connected between an RF signal line and ground. The gate terminal of the solid state switch is capacitively coupled to the switch terminal (i.e. drain or source) connected to the RF signal line, forcing the gate bias element to become a fixed, rather than switched, load, thereby minimizing errors due to the gate biasing element and enabling tuning reactances to be used to compensate for such gate loads.

What is claimed and desired to be secured by Letters Patent of the United States is: 
     
       1. An attenuator control circuit for an RF signal line comprising: a signal splitter for splitting said RF signal line into a first branch and a second branch;   a first switched attenuator which includes a first solid state switch and a first resistance coupled between said first branch and ground;   a second switched attenuator which includes a second solid state switch and a second resistance coupled between said second branch and ground; and   a signal recombiner for combining said first and second branches.   
     
     
       2. An attenuator control circuit as recited in claim 1, wherein said first and second branches are of equal power. 
     
     
       3. An attenuator control circuit as recited in claim 1, wherein said first and second branches are of unequal power.